Some people watch scary movies because they like being startled. A bad guy jumps out from around a corner! A monster emerges from the shadows! Scientists experience surprises all the time, but they’re usually more excited than scared. Sometimes theories foreshadow new findings — like when there’s a dramatic swell in the movie soundtrack — but often, discoveries are truly unexpected.
Scientists working with the Fermi Gamma-Ray Space Telescope have been jumping to study mysterious bumps in the gamma rays for a decade now. Gamma rays are the highest-energy form of light. Invisible to human eyes, they’re created by some of the most powerful and unusual events and objects in the universe. In celebration of Halloween, here are a few creepy gamma-ray findings from Fermi’s catalog.
Stellar Graveyards
If you were to walk through a cemetery at night, you’d expect to trip over headstones or grave markers. Maybe you’d worry about running into a ghost. If you could explore the stellar gravesite created when a star explodes as a supernova, you’d find a cloud of debris expanding into interstellar space. Some of the chemical elements in that debris, like gold and platinum, go on to create new stars and planets! Fermi found that supernova remnants IC 443 and W44 also accelerate mysterious cosmic rays, high-energy particles moving at nearly the speed of light. As the shockwave of the supernova expands, particles escape its magnetic field and interact with non-cosmic-ray particles to produce gamma rays.
Ghost Particles
But the sources of cosmic rays aren’t the only particle mysteries Fermi studies. Just this July, Fermi teamed up with the IceCube Neutrino Observatory in Antarctica to discover the first source of neutrinos outside our galactic neighborhood. Neutrinos are particles that weigh almost nothing and rarely interact with anything. Around a trillion of them pass through you every second, ghost-like, without you noticing and then continue on their way. (But don’t worry, like a friendly ghost, they don’t harm you!) Fermi traced the neutrino IceCube detected back to a supermassive black hole in a distant galaxy. By the time it reached Earth, it had traveled for 3.7 billion years at almost the speed of light!
Black Widow Pulsars
Black widows and redbacks are species of spiders with a reputation for devouring their partners. Astronomers have discovered two types of star systems that behave in a similar way. Sometimes when a star explodes as a supernova, it collapses back into a rapidly spinning, incredibly dense star called a pulsar. If there’s a lighter star nearby, it can get stuck in a close orbit with the pulsar, which blasts it with gamma rays, magnetic fields and intense winds of energetic particles. All these combine to blow clouds of material off the low-mass star. Eventually, the pulsar can eat away at its companion entirely.
Dark Matter
What’s scarier than a good unsolved mystery? Dark matter is a little-understood substance that makes up most of the matter in the universe. The stuff that we can see — stars, people, haunted houses, candy — is made up of normal matter. But our surveys of the cosmos tell us there’s not enough normal matter to keep things working the way they do. There must be another type of matter out there holding everything together. One of Fermi’s jobs is to help scientists narrow down the search for dark matter. Last year, researchers noticed that most of the gamma rays coming from the Andromeda galaxy are confined to its center instead of being spread throughout. One possible explanation is that accumulated dark matter at the center of the galaxy is emitting gamma rays!
Fermi has helped us learn a lot about the gamma-ray universe over the last 10 years. Learn more about its accomplishments and the other mysteries it’s working to solve. What other surprises are waiting out among the stars?
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
A team of eight scientists including our own Astromaterials Curation Chief Cindy Evans spent two-months in the frozen landscape of Antarctica as part of the Antarctic Search for Meteorites (ANSMET), a 40-year program that has helped reveal information about asteroids, other bodies of our solar system and the red planet which will assist us on our Journey to Mars.
The team recovered nearly 570 new meteorite samples from the Miller Range of the Trans-Antarctic Mountains during the expedition.
After a several-month journey from Antarctica, these samples arrived at our Johnson Space Center in Houston, Texas, on April 14 to become part of the U.S. Antarctic meteorite collection housed at Johnson and the Smithsonian Institution in Washington, D.C.
Samples recovered from recent seasons include rare and scientifically valuable pieces of Mars and Moon, as well as rocks formed very early during the formation and evolution of the solar system that hold clues to the origin of volatiles, planets and the organic compounds essential to life.
Meteorites are currently the only way to acquire samples from Mars as well as new samples of the moon that are different from – and originated far from – the Apollo landing sites, as well as a variety of asteroid bodies.
Samples from this collection (representing nearly 40 individual collection seasons) are available to researchers worldwide, and hundreds are distributed every year by the Astromaterials Curation Office.
The meteorites collected give us important clues about the early solar system, but even the thousands of meteorites recovered over the years represent a tiny part of the larger puzzle, including a find in the 1990s that produced evidence that sparked a vigorous debate about whether life could have existed on Mars more than 3.6 billion years ago.
As engineers and scientists around the country work hard to develop the technologies astronauts will use to one day live and work on Mars, and safely return home from the next giant leap for humanity, the meteorites provide critical data that enable engineers to build the right technologies.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
3 … 2 … 1… ALOHA!
Sometimes in space, you have to set your clocks to island time and gather for a good Hawaiian shirt day. In this 2001 #TBT, Expedition Two and STS-100 crew members gather for a group photo with a pre-set digital still camera.
Clockwise from the 12 o'clock point in the circle are Kent V. Rominger, Yuri V. Lonchakov, Yury V. Usachev, Umberto Guidoni, James S. Voss, Jeffrey S. Ashby, Scott E. Parazynski, John L. Phillips and Chris A. Hadfield, with Susan J. Helms at center. Usachev, Helms and Voss are members of three Expedition Two crew, with the other seven serving as the STS-100 crew on the Space Shuttle Endeavour. Usachev and Lonchakov represent Rosaviakosmos; Guidoni is associated with the European Space Agency (ESA); and Hadfield is from the Canadian Space Agency (CSA).
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
The twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing their more-than-40-year journey since their 1977 launches, they each are much farther away from Earth and the Sun than Pluto.
The primary mission was the exploration of Jupiter and Saturn. After making a string of discoveries there – such as active volcanoes on Jupiter’s moon Io and intricacies of Saturn’s rings – the mission was extended.
Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer planets. The adventurers’ current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun’s domain. And beyond.
‘BUS’ Housing Electronics
The basic structure of the spacecraft is called the “bus,” which carries the various engineering subsystems and scientific instruments. It is like a large ten-sided box. Each of the ten sides of the bus contains a compartment (a bay) that houses various electronic assemblies.
Cosmic Ray Subsystem (CRS)
The Cosmic Ray Subsystem (CRS) looks only for very energetic particles in plasma, and has the highest sensitivity of the three particle detectors on the spacecraft. Very energetic particles can often be found in the intense radiation fields surrounding some planets (like Jupiter). Particles with the highest-known energies come from other stars. The CRS looks for both.
High-Gain Antenna (HGA)
The High-Gain Antenna (HGA) transmits data to Earth on two frequency channels (the downlink). One at about 8.4 gigahertz, is the X-band channel and contains science and engineering data. For comparison, the FM radio band is centered around 100 megahertz.
Imaging Science Subsystem (ISS)
The Imaging Science Subsystem (ISS) is a modified version of the slow scan vidicon camera designed that were used in the earlier Mariner flights. The ISS consists of two television-type cameras, each with eight filters in a commandable Filter Wheel mounted in front of the vidicons. One has a low resolution 200 mm wide-angle lens, while the other uses a higher resolution 1500 mm narrow-angle lens.
Infrared Interferometer Spectrometer and Radiometer (IRIS)
The Infrared Interferometer Spectrometer and Radiometer (IRIS) actually acts as three separate instruments. First, it is a very sophisticated thermometer. It can determine the distribution of heat energy a body is emitting, allowing scientists to determine the temperature of that body or substance.
Second, the IRIS is a device that can determine when certain types of elements or compounds are present in an atmosphere or on a surface.
Third, it uses a separate radiometer to measure the total amount of sunlight reflected by a body at ultraviolet, visible and infrared frequencies.
Low-Energy Charged Particles (LECP)
The Low-Energy Charged Particles (LECP) looks for particles of higher energy than the Plasma Science instrument, and it overlaps with the Cosmic Ray Subsystem (CRS). It has the broadest energy range of the three sets of particle sensors.
The LECP can be imagined as a piece of wood, with the particles of interest playing the role of the bullets. The faster a bullet moves, the deeper it will penetrate the wood. Thus, the depth of penetration measures the speed of the particles. The number of “bullet holes” over time indicates how many particles there are in various places in the solar wind, and at the various outer planets. The orientation of the wood indicates the direction from which the particles came.
Magnetometer (MAG)
Although the Magnetometer (MAG) can detect some of the effects of the solar wind on the outer planets and moons, its primary job is to measure changes in the Sun’s magnetic field with distance and time, to determine if each of the outer planets has a magnetic field, and how the moons and rings of the outer planets interact with those magnetic fields.
Optical Calibration Target The target plate is a flat rectangle of known color and brightness, fixed to the spacecraft so the instruments on the movable scan platform (cameras, infrared instrument, etc.) can point to a predictable target for calibration purposes.
Photopolarimeter Subsystem (PPS)
The Photopolarimeter Subsystem (PPS) uses a 0.2 m telescope fitted with filters and polarization analyzers. The experiment is designed to determine the physical properties of particulate matter in the atmospheres of Jupiter, Saturn and the rings of Saturn by measuring the intensity and linear polarization of scattered sunlight at eight wavelengths.
The experiment also provided information on the texture and probable composition of the surfaces of the satellites of Jupiter and Saturn.
Planetary Radio Astronomy (PRA) and Plasma Wave Subsystem (PWS)
Two separate experiments, The Plasma Wave Subsystem and the Planetary Radio Astronomy experiment, share the two long antennas which stretch at right-angles to one another, forming a “V”.
Plasma Science (PLS)
The Plasma Science (PLS) instrument looks for the lowest-energy particles in plasma. It also has the ability to look for particles moving at particular speeds and, to a limited extent, to determine the direction from which they come.
The Plasma Subsystem studies the properties of very hot ionized gases that exist in interplanetary regions. One plasma detector points in the direction of the Earth and the other points at a right angle to the first.
Radioisotope Thermoelectric Generators (RTG)
Three RTG units, electrically parallel-connected, are the central power sources for the mission module. The RTGs are mounted in tandem (end-to-end) on a deployable boom. The heat source radioisotopic fuel is Plutonium-238 in the form of the oxide Pu02. In the isotopic decay process, alpha particles are released which bombard the inner surface of the container. The energy released is converted to heat and is the source of heat to the thermoelectric converter.
Ultraviolet Spectrometer (UVS)
The Ultraviolet Spectrometer (UVS) is a very specialized type of light meter that is sensitive to ultraviolet light. It determines when certain atoms or ions are present, or when certain physical processes are going on.
The instrument looks for specific colors of ultraviolet light that certain elements and compounds are known to emit.
Learn more about the Voyager 1 and 2 spacecraft HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Our @NASAJuno spacecraft's JunoCam captured images of the chaotic, stormy northern hemisphere of Jupiter during its 24th close pass of the giant planet on Dec. 26, 2019. Using data from the flyby, citizen scientist Kevin M. Gill created this color-enhanced image. At the time, the spacecraft was about 14,600 miles (23,500 kilometers) from the tops of Jupiter’s clouds, at a latitude of about 69 degrees north.
Image Credit: Image data: NASA/JPL-Caltech/SwRI/MSSS
Image processing by Kevin M. Gill, © CC BY
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
What can you see from the space station? Can you see stars, the moon and sun, and Earth weather like lightening storms?
Happy New Year! And happy supermoon! Tonight, the Moon will appear extra big and bright to welcome us into 2018 – about 6% bigger and 14% brighter than the average full Moon. And how do we know that? Well, each fall, our science visualizer Ernie Wright uses data from the Lunar Reconnaissance Orbiter (LRO) to render over a quarter of a million images of the Moon. He combines these images into an interactive visualization, Moon Phase and Libration, which depicts the Moon at every day and hour for the coming year.
Want to see what the Moon will look like on your birthday this year? Just put in the date, and even the hour (in Universal Time) you were born to see your birthday Moon.
Our Moon is quite dynamic. In addition to Moon phases, our Moon appears to get bigger and smaller throughout the year, and it wobbles! Or at least it looks that way to us on Earth. This wobbling is called libration, from the Latin for ‘balance scale’ (libra). Wright relies on LRO maps of the Moon and NASA orbit calculations to create the most accurate depiction of the 6 ways our Moon moves from our perspective.
The Moon phases we see on Earth are caused by the changing positions of the Earth and Moon relative to the Sun. The Sun always illuminates half of the Moon, but we see changing shapes as the Moon revolves around the Earth. Wright uses a software library called SPICE to calculate the position and orientation of the Moon and Earth at every moment of the year. With his visualization, you can input any day and time of the year and see what the Moon will look like!
Check out that crater detail! The Moon is not a smooth sphere. It’s covered in mountains and valleys and thanks to LRO, we know the shape of the Moon better than any other celestial body in the universe. To get the most accurate depiction possible of where the sunlight falls on the lunar surface throughout the month, Wright uses the same graphics software used by Hollywood design studios, including Pixar, and a method called ‘raytracing’ to calculate the intricate patterns of light and shadow on the Moon’s surface, and he checks the accuracy of his renders against photographs of the Moon he takes through his own telescope.
The Moon Phase and Libration visualization shows you the apparent size of the Moon. The Moon’s orbit is elliptical, instead of circular - so sometimes it is closer to the Earth and sometimes it is farther. You’ve probably heard the term “supermoon.” This describes a full Moon at or near perigee (the point when the Moon is closest to the Earth in its orbit). A supermoon can appear up to 14% bigger and brighter than a full Moon at apogee (the point when the Moon is farthest from the Earth in its orbit).
Our supermoon tonight is a full Moon very close to perigee, and will appear to be about 14% bigger than the July 27 full Moon, the smallest full Moon of 2018, occurring at apogee. Input those dates into the Moon Phase and Libration visualization to see this difference in apparent size!
Over a month, the Moon appears to nod, twist, and roll. The east-west motion, called ‘libration in longitude’, is another effect of the Moon’s elliptical orbital path. As the Moon travels around the Earth, it goes faster or slower, depending on how close it is to the Earth. When the Moon gets close to the Earth, it speeds up thanks to an additional pull from Earth’s gravity. Then it slows down, when it’s farther from the Earth. While this speed in orbital motion changes, the rotational speed of the Moon stays constant.
This means that when the Moon moves faster around the Earth, the Moon itself doesn’t rotate quite enough to keep the same exact side facing us and we get to see a little more of the eastern side of the Moon. When the Moon moves more slowly around the Earth, its rotation gets a little ahead, and we see a bit more of its western side.
The Moon also appears to nod, as if it were saying “yes,” a motion called ‘libration in latitude’. This is caused by the 5 degree tilt of the Moon’s orbit around the Earth. Sometimes the Moon is above the Earth’s northern hemisphere and sometimes it’s below the Earth’s southern hemisphere, and this lets us occasionally see slightly more of the northern or southern hemispheres of the Moon!
Finally, the Moon appears to tilt back and forth like a metronome. The tilt of the Moon’s orbit contributes to this, but it’s mostly because of the 23.5 degree tilt of our own observing platform, the Earth. Imagine standing sideways on a ramp. Look left, and the ramp slopes up. Look right and the ramp slopes down.
Now look in front of you. The horizon will look higher on the right, lower on the left (try this by tilting your head left). But if you turn around, the horizon appears to tilt the opposite way (tilt your head to the right). The tilted platform of the Earth works the same way as we watch the Moon. Every two weeks we have to look in the opposite direction to see the Moon, and the ground beneath our feet is then tilted the opposite way as well.
So put this all together, and you get this:
Beautiful isn’t it? See if you can notice these phenomena when you observe the Moon. And keep coming back all year to check on the Moon’s changing appearance and help plan your observing sessions.
Follow @NASAMoon on Twitter to keep up with the latest lunar updates.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
October 28th is International Observe the Moon Night, a worldwide, public celebration of lunar science and exploration held annually since 2010 thanks to our Lunar Reconnaissance Orbiter (LRO) mission team and partners. One day each year, everyone on Earth is invited to observe and learn about the Moon together, and to celebrate the cultural and personal connections we all have with our planet’s nearest neighbor.
1. There has been a spacecraft there for 100 lunar days
In October 2017, LRO celebrates one hundred days of collecting scientific data at the Moon. One hundred Moon days. From our perspective on Earth, one lunar day is one full phase cycle, or about 29.5 Earth days. That's 100 opportunities to observe changes from night to day, photograph the surface at different Sun angles, measure rising and falling temperatures, study the way certain chemicals react to the daily light and temperature cycle, and increase our understanding of the Moon as a dynamic place.
2. You can still see the paths left by Apollo astronauts’ boot prints and rovers
Much of the lunar surface is covered in very fine dust. When Apollo astronauts landed on the Moon, the descent stage engine disturbed the dust and produced a distinct bright halo around the lunar module. As astronauts moved around, their tracks exposed the darker soil underneath, creating distinct trails that we know, thanks to LRO, are still visible today. The Moon has no atmosphere, so there is no wind to wipe away these tracks.
3. The Moon has tattoos!
Observations from LRO show mysterious patterns of light and dark that are unique to the Moon. These lunar swirls look painted on, like the Moon got ‘inked.’ Lunar swirls, like these imaged at Reiner Gamma by LRO, are found at more than 100 locations across the lunar surface. Lunar swirls can be tens of miles across and appear in groups or as isolated features.
Researchers think these patterns form in places where there’s still a remnant of the Moon’s magnetic field. There are still many competing theories about how swirls form, but the primary idea is that the local magnetic field deflects the energetic particles in the solar wind, so there’s not as much weathering of the surface. The magnetically shielded areas would then look brighter than everything around them.
4. There were once active volcanoes, that shaped what we see now
Early astronomers named the large dark spots that we see on the near side of the Moon “maria,” Latin for “seas,” because that’s what they thought they were. We now know that the dark spots are cooled lava, called basalt, formed from ancient volcanic eruptions. The Moon’s volcanoes are no longer active, but their past shapes the Moon that we see today. The Moon doesn’t have large volcanoes like ones in Hawaii, but it does have smaller cones and domes.
Other small features derived from volcanic activity include rivers of dried lava flows, like the ones visible in this image of Vallis Schroteri taken by LRO, and dark areas formed from eruptive volcanoes that spewed fire. For many years, scientists thought the Moon’s volcanic activity died out long ago, but there’s some evidence for relatively “young” volcanism, suggesting that the activity gradually slowed down instead of stopping abruptly.
5. Anyone, anywhere can participate in International Observe the Moon Night.
How to celebrate International Observe the Moon Night
Attend an event – See where events are happening near you by visiting http://observethemoonnight.org
Host an event – Call up your neighbors and friends and head outdoors – no special equipment is needed. Let us know how you celebrated by registering your event!
Don’t let cloudy weather get you down! Observe the Moon in a variety of ways from the comfort of indoors – View stunning lunar vistas through images and videos, or explore the Moon on your own with QuickMap or Moon Trek
Join the worldwide conversation with #ObserveTheMoon on Twitter, Instagram and Facebook
For regular Moon-related facts, updates and science, follow @NASAMoon on Twitter
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
How does the whole sleeping situation work with 0 gravity, or do sleep mid air?
Does Webb have resolution to look more closely at nearby objects, like Mars or even Earth? Or just far things?
What's next for NASA? In 2019, we’re once again preparing for human missions to the Moon. We're keeping the promise by developing new systems and spacecraft, making innovations in flight and technology, living and doing science on the International Space Station, and delivering images and discoveries from our home planet, our solar system and beyond.
Check out What’s Next for NASA: https://www.nasa.gov/next
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Explore the universe and discover our home planet with the official NASA Tumblr account
1K posts